1. Field of the Invention
The present invention relates to aluminum-based alloys having a desired combination of properties of high corrosion-resistance, high hardness, high wear-resistance and high heat-resistance.
2. Description of the Prior Art
As conventional aluminum-based alloys, there have been known various types of aluminum-based alloys, such as Al-Cu, Al-Si, Al-Mg, Al-Cu-Si, Al-Cu-Mg, Al-Zn-Mg alloys, etc. These aluminum-based alloys have been extensively used in a wide variety of applications, such as structural materials for aircrafts, cars, ships or the like; outer building materials, sash, roof, etc; structural materials for marine apparatuses and nuclear reactors, etc., according to their properties.
In order to obtain high corrosion resistance, the conventional aluminum-based alloys have usually been subjected to special treatments, for example, anodizing treatment or coating treatment with organic or inorganic substances by painting or electrolytic deposition. However, such known treatments may complicate the production procedure of the above mentioned structural materials and result in increased production cost. Further, depending on the shapes, for example, as referred to structural or building materials or piping materials having complicated shapes, it may be impossible or difficult to form corrosion-resistant protective coatings. Therefore, satisfactory corrosion resistance has not been achieved up to now.
Further, the conventional aluminum-based alloys generally have a low hardness and a low heat resistance. Recently, attempts have been made to impart a fine-structure to aluminum-based alloys by rapidly solidifing the alloys and thereby improve the mechanical properties, such as strength, and chemical properties, such as corrosion resistance. However, the rapidly solidified aluminum-based alloys known up to now are still unsatisfactory in strength, corrosion resistance, etc.